9.1.3 EXPERIMENTAL MOUSE SHARED SERVICE The Experimental Mouse Shared Service (EMSS) is a one-stop shared service for all your in vivo mouse experimentation needs. The purpose of the EMSS is to provide investigators at the Arizona Cancer Center (AZCC) with experimental mouse models and with a wide range of mouse experimentation techniques. The EMSS has combined the previous Genetically Engineered Mouse "Developmental" Shared Service (GEMSS) and the previous EMSS. Therefore, the EMSS begins with the design and construction of gene targeting and transgenic mouse vectors, gene targeting and ES cell screening for targeted Clones, production of genetargeted mice, production of transgenic mice, screening for transgenic and knockout founders, embryo rederivation for pathogen cleanup and cryopreservation of mouse strains through to complete experimentation services in all aspects of xenograft and GEM models. The specific objectives of the EMSS include creation of models, maintenance of shared and investigator colonies, assistance in the design of in vivo experiments, and performance of mouse experiments by personnel with expertise in mouse experimental protocols. Hence, the EMSS provides consistency and quality of procedures within and between mouse experiments that ensures accuracy in experimental results, confidence in interpretation of results, and an inner-consistency between mouse experiments which is essential for intra-lab and inter-lab comparative analyses. Due to the fact that the mouse is a model for all translational cancer work for both NIH-type funding as well as progression to clinical trials, the EMSS is an absolutely essential shared service. The benefits of the EMSS are to provide AZCC investigators with a cost-effective mechanism for the creation of different mouse models and for completing in vivo mouse experiments utilizing highly trained and experienced technicians. The EMSS continues to expand its services in a very cost-effective and efficient manner.